296 N^oies and Commcnis. 



some years past certain ornithologists have directed attention 

 to the decreasing number of swallows seen in the British 

 Isles during the months from April to September. This 

 diminution was particularly marked in 1918 and 1919, less 

 so in 1920, but is still more apparent in the present year. For 

 a time the scarcity was denied by many, or stated to be only 

 of local occurrence, but the condition of affairs during the 

 present season is sufficiently well marked to convince the most 

 sceptical. The swallow, economicall^^ is one of our most 

 valuable birds, its food consisting practically entirely of 

 insects, and any scarcity of these birds removes a most import- 

 ant factor in the destruction of injurious insects. The causes 

 which have led to the scarcity are not at present all known, 

 but there are some which have been operating for a considerable 

 time past, and their effects are now making themselves felt. 

 In view of the importance of the swallows, economically, 

 the question is one calling for immediate attention and 

 investigation, and until we know more about the matter 

 it might be well to place this bird and its eggs under stricter 

 protection.' 



CUP AND RING MARKINGS. 



Mr. C. Carus-Wilson suggests that ' cup and ring ' markings 

 which occur on ' calcareous sandstones,' etc., ' are due to 

 molecular re -arrangement of the calcium carbonate, and not 

 to any artistic effort on the part of prehistoric man, as is 

 frequently supposed.' He points out that similar patterns 

 occur on ' American Cloth ' and on old oil paintings. We 

 are not surprised that Mr. Carus-Wilson should hold these 

 views, but we are surprised that Nature should publish them. 



BUREAU OF BIO-TECHNOLOGV. 



We have received Bulletin No. 3 of this Bureau, in which 

 the Director, Mr. F. A. Mason, has a scholarly paper on 

 ' Micro-organisms in the Leather Industries ; a systematic 

 arrangement of the Fungi mentioned in the literature of the 

 Leather Technology,' and Mr. P. Hampshire describes ' a 

 method of Determining Hydrogen Ion Concentration." 

 There are half-a-dozen pages of ' Notes and Comments,' 

 etc., which are flatteringly like a certain column bearing the 

 same title we wot of ! 



BARLEY PESTS. 



Mr. F. A. Mason has a lengthy paper on ' Pests and 

 Diseases of Barley and Malt, Part I., Injurious Insects,' 

 in Vol. XXVII. of The Journal of the Institute of Breicing, 

 for July. He gives startling figures as to the loss to barley 

 crops through the depredations of insects. He concludes 

 that to control these pests in makings and breweries there ■ 



